A novel high-temperature durable graphene temperature sensor with nano composite protective layer

Temperature monitoring is widely applied across various industries, with temperature sensors being essential for monitoring temperature conditions in processes within the fields such as aerospace, industrial production, and healthcare. However, most existing traditional temperature sensors operate at temperatures below 200 °C, which fails to meet the high-temperature monitoring requirements of many application scenarios. Therefore, we propose a graphene-based high-temperature durable temperature sensor with a composite protective layer composed of silicon nitride (SiN_x) and aluminum oxide (Al₂O₃). This novel composite protective layer effectively prevents the oxidation of graphene at high temperatures, enabling the temperature sensor to operate over extended periods under such conditions. The sensor has a maximum tolerance temperature of 600 °C and a temperature measurement range of 50 °C-600 °C. The resistance of the device increases with rising temperature, exhibiting a positive temperature coefficient, with a maximum average temperature coefficient of resistance value of 0.17 ± 0.015% °C^-1(mean ± s.d.,n= 3). Critically, experimental tests have demonstrated that our temperature sensor not only offers a wide temperature measurement range but also can continuously operate for over four hours at extremely high temperatures (500 °C). This study addresses the challenge of graphene's inability to function over the long term at high temperatures by proposing a new protective structure, holding promise for applications in long-term high-temperature scenarios such as energy and power generation and metallurgical processes.